ES2039517T3 - PROCEDURE FOR DAMPING NOISE FOR AN OPTICAL SCAN DEVICE. - Google Patents

PROCEDURE FOR DAMPING NOISE FOR AN OPTICAL SCAN DEVICE.

Info

Publication number
ES2039517T3
ES2039517T3 ES198888111951T ES88111951T ES2039517T3 ES 2039517 T3 ES2039517 T3 ES 2039517T3 ES 198888111951 T ES198888111951 T ES 198888111951T ES 88111951 T ES88111951 T ES 88111951T ES 2039517 T3 ES2039517 T3 ES 2039517T3
Authority
ES
Spain
Prior art keywords
photodetector
order
recording medium
data signal
optical recording
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
ES198888111951T
Other languages
Spanish (es)
Inventor
Yasuaki Morimoto
Friedhelm Zucker
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deutsche Thomson Brandt GmbH
Original Assignee
Deutsche Thomson Brandt GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Deutsche Thomson Brandt GmbH filed Critical Deutsche Thomson Brandt GmbH
Application granted granted Critical
Publication of ES2039517T3 publication Critical patent/ES2039517T3/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
    • G11B11/10532—Heads
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
    • G11B11/10502—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing characterised by the transducing operation to be executed
    • G11B11/10515—Reproducing
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
    • G11B11/10532—Heads
    • G11B11/10541—Heads for reproducing
    • G11B11/10543—Heads for reproducing using optical beam of radiation
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
    • G11B11/1055—Disposition or mounting of transducers relative to record carriers
    • G11B11/10576—Disposition or mounting of transducers relative to record carriers with provision for moving the transducers for maintaining alignment or spacing relative to the carrier

Abstract

When operating an optical pick-up device for scanning a magneto-optical recording medium (6) on the basis of the three-beam method, that main beam of which the polarisation plane is turned in one direction is reflected by the magnetic-optical recording medium onto a first photodetector (11) and that main beam of which the polarisation plane is turned in the other direction is reflected by the magneto-optical recording medium onto a second photodetector (12). The data signal is formed from the difference between the photoelectric voltages of the first photodetector and the second photodetector. In order to avoid interfering noise in the data signal, the second photodetector is adjusted so accurately that it is impinged only by the main beam, but not by the diffraction products higher and lower than the 0th order. <??>In order to reduce the noise in the data signal S without having to adjust the second photodetector (12) accurately to do so, the beams higher than the + 1st order and lower than the - 1st order are also reflected by the magneto-optical recording medium (6) onto the second photodetector (12). To generate the data signal (S) at least the photoelectric voltages generated by the beams of the + 1st order and - 1st order are subtracted from the photoelectric voltage of the second photodetector (12). Therefore, a relatively large second photodetector can be chosen and it need not be adjusted accurately. <IMAGE>
ES198888111951T 1987-09-30 1988-07-25 PROCEDURE FOR DAMPING NOISE FOR AN OPTICAL SCAN DEVICE. Expired - Lifetime ES2039517T3 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19873732944 DE3732944A1 (en) 1987-09-30 1987-09-30 OPTICAL SCANNER

Publications (1)

Publication Number Publication Date
ES2039517T3 true ES2039517T3 (en) 1993-10-01

Family

ID=6337224

Family Applications (1)

Application Number Title Priority Date Filing Date
ES198888111951T Expired - Lifetime ES2039517T3 (en) 1987-09-30 1988-07-25 PROCEDURE FOR DAMPING NOISE FOR AN OPTICAL SCAN DEVICE.

Country Status (10)

Country Link
US (1) US4959821A (en)
EP (1) EP0309675B1 (en)
JP (1) JP2907842B2 (en)
KR (1) KR960016890B1 (en)
CN (1) CN1012115B (en)
AT (1) ATE86776T1 (en)
DE (2) DE3732944A1 (en)
DK (1) DK547988A (en)
ES (1) ES2039517T3 (en)
HU (1) HUT61120A (en)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5644554A (en) * 1988-01-19 1997-07-01 Hitachi, Ltd. Magnetic head load/unload device, method and a magneto-optical disk apparatus using the same
US5182735A (en) * 1989-03-06 1993-01-26 Eastman Kodak Company Magneto-optic readout apparatus using polarization switching of readout beam
US5235570A (en) * 1989-03-06 1993-08-10 Eastman Kodak Company Magneto-optic readout method and apparatus using polarization switching of readout beam
US5712840A (en) * 1990-03-16 1998-01-27 Canon Kabushiki Kaisha Optical information recording/reproduciing apparatus having two-division detectors
DE69126160T2 (en) * 1990-03-16 1997-10-09 Canon Kk Optical information recording / reproducing apparatus
US5119352A (en) * 1990-08-17 1992-06-02 Hewlett-Packard Company Magneto optic data storage read out apparatus and method
DE4026875A1 (en) * 1990-08-25 1992-02-27 Thomson Brandt Gmbh OPTICAL SCANNER
MY139800A (en) * 1991-06-04 2009-10-30 Mitsubishi Electric Corp Multiple data surface data storage system and method
DE4205851C2 (en) * 1992-02-26 1995-10-12 Flachglas Ag Antenna pane to be inserted into the window opening of a metallic motor vehicle body
JPH05282723A (en) * 1992-03-31 1993-10-29 Matsushita Electric Ind Co Ltd Magnetooptic head device
EP0582059B1 (en) * 1992-06-02 1998-05-13 Nec Corporation Magneto-optical head assembly
US5349576A (en) * 1992-07-27 1994-09-20 Eastman Kodak Company Apparatus and method for polarization switching of a readout beam in a magneto-optic storage system
DE4226777A1 (en) * 1992-08-13 1994-02-17 Thomson Brandt Gmbh Noise reduction in the data signal and optical scanning device

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5963040A (en) * 1982-09-16 1984-04-10 Canon Inc Optical magnetic information reader
JPS5958637A (en) * 1982-09-28 1984-04-04 Sony Corp Optical reproducing device
US4691308A (en) * 1984-04-19 1987-09-01 Nippon Kogaku K. K. Apparatus for reproducing information from magnetooptical recording medium

Also Published As

Publication number Publication date
KR890005686A (en) 1989-05-16
DE3732944A1 (en) 1989-04-13
JPH01106348A (en) 1989-04-24
EP0309675A1 (en) 1989-04-05
EP0309675B1 (en) 1993-03-10
HUT61120A (en) 1992-11-30
ATE86776T1 (en) 1993-03-15
US4959821A (en) 1990-09-25
DK547988D0 (en) 1988-09-30
DK547988A (en) 1989-03-31
CN1032599A (en) 1989-04-26
JP2907842B2 (en) 1999-06-21
CN1012115B (en) 1991-03-20
DE3879064D1 (en) 1993-04-15
KR960016890B1 (en) 1996-12-26

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